Powder coating can utilize various materials. Among the most common thermoset polymers are acrylics, fusion bonded epoxy (straight epoxy, polyester-epoxy (hybrid epoxy) polyester and polyurethane. For those who focus on indoor use only, an epoxy powder coating is the most popular choice.
Epoxy and Polyester-Epoxy Powder Coatings
Epoxy is a durable and hard resin possessing many desirable qualities. As a coating to many substrate surfaces, epoxy – in both straight and hybrid formats, provides improved impact resistance. This means the component can withstand a certain amount of external and unexpected force. In addition, epoxy powder coatings contribute two other important characteristics. These are:
1. Corrosion resistance
2. Adhesion
Such properties make an epoxy powder coating popular for certain applications. They find use as coatings for specific industrial equipment, as the underbody components of many vehicles and for metal furniture and appliance.
Indoor Use Only
However, the use of epoxy, even the stronger, hybrid version, comes with a major precaution. It is not for exterior use. Epoxy-based coatings do not withstand the effects of UV rays. UV exposure reduces their glossy appearance and can result in chalking. As a result, even though epoxy coatings can provide protection against the corrosive effects of marine (salt) spray, they need to do so while being kept out of the range of UV rays.
It is important to note two things in regards to this susceptibility:
1. In hybrid form, it will still chalk and fade
2. Applying a clear coat on top – even if this coating has an exterior use rating, will not alter the situation. The epoxy resin will quickly chalk up
Epoxy Powder Coating
Epoxy powder coatings offer components many advantages. They are durable and provide protection against corrosion and caustic substances to the substrate. However, they are not capable of expecting damage from UV rays. If you are considering an epoxy powder coating, be sure the components are intended for an interior environment.
